Esophageal squamous cell carcinoma has highly variable rates across countries and even across different regions within countries such as China and Iran. This makes it an important cancer for studying genetic, environmental and infection etiological relationships. We are currently studying gene methylation in the progression of ESCC and have selected genes that have a high prevalence of methylation in tumors and that occur early is dysplasia with the goal of evaluating early detection markers in this screening study. The CSS2 was conducted to estimate the sensitivity of the newly designed esophageal cytology sampler for detecting squamous dysplasia and carcinoma (ESCC) in comparison with the standard balloon cytology sampling device. We are evaluating gene methylation in the cytology samples to predict esophageal dysplasia/cancer and to facilitate the large-scale screening of high-risk populations. Thus far, we have identified a panel of ten genes that are methylated early in carcinogenesis (observed in highrage dysplasia and cancer lesions). Several of these genes were found to be methylated in balloon cytology specimens obtained from subjects (with no known histologic diagnosis) from this region of China, confirming that balloon specimens may be useful for the early detection of ESCC.